Not all today but over the past few weeks, I've finally got around to tidying up my LPG install. I replaced the vaporiser that I think it was a bit underpowered for the car and the seals protruding the edges didn't look too healthy either.
I should also mention I replaced the MAF for a new Bosch one, as I have had some errors related to fuel trims etc and on a closer look, it was actually a cheap one, whilst I'd been thinking it was a Bosch one :/ After this I reset the adaptive values and cleared the codes, but just like usual they returned after a short drive.
Last week I then continued with the LPG, cleaned up the hose routes to the injector rails, routing them towards the rear of the engine instead of straight over the oil filler cap... Plus replaced all the injector hoses and clamps, filter etc. Then cleaned up the wiring loom route too. Finally after buying a diagnostic cable eventually, I looked at the map and found the culprit of the weird dip in revs when idling on LPG only, with AC on. It was set to cut back to petrol at below 800rpm and over 3000rpm, whilst also leaving the petrol injectors open... So what I discovered was happening was, as the AC engaged/disengaged at idle, it would sometimes cause the revs to change just enough for the LPG to switch from petrol to gas and then immediately back again... As it would jump up slightly and hit 800rpm.
So I had a look online for some info on LPG maps for the controller I have and started to tweak. First I turned off the conditions for secretly switching back to petrol at different revs. I let it run an auto map at idle to start with and things were immediately a little better (also pretty far from the previous map!), then I adjusted the map manually a little. Cleared the fault codes for the engine, reset adaptive values again and when for a short drive on both petrol and then gas. Things look good on the map and the engine felt even smoother, gear changes feel almost unnoticeable too now, when sometimes I'd feel those a little more than I liked.
Yesterday I decided to look at another job I've been putting off, which was an error for a heater blower motor not working. First check, the relays... It's missing... I've never even given the 2 missing relays a thought, as I expected they'd be for features I didn't have installed. One is a windscreen heater (makes sense, as I don't have that) but the other was a blower motor! Popped one in and all working. Cleared the fault code and also had a look back at the motronic errors and after a week, no more fuel trim errors! Looks like the LPG setup that I thought was working relatively well but just messy, was actually pretty poor.
So now with those errors sorted, not a single error code :)
But... Of course new things to do, I've noticed that my front diff is leaking a bit, with a splash and layer of diff oil slapped around the underside. Looks to be from the pinion seal area, so need to get a pinion and flange kit ordered. I checked the breather hose and that seems to not be blocked though, so probably just a worn seal.
I also poked around to see where my minor engine oil leak is coming from. For a long time I've thought it was the rear main. However I opened the inspection hole in the bell housing and surprisingly it's perfectly dry in there, only a touch of oil on the removable plate itself. It gathers on the bottom of the sump and drain bolt, or a little on the join between the sump and bell housing. It leaves a couple of drops on the driveway, but nothing major. Looking around again, maybe it's from around the front cover area? The front seal was replaced when I recently did a partial engine rebuild with new cam etc. It looks like it might be from the cam position sensor or to the side of this?! It's completely dry above the cam sensor and all the heads, water pump etc, so it's not a valley gasket or rocker cover gasket. It also doesn't seem to be from the oil cooler lines either. I'm going to replace the seal again on the cam sensor to be sure and if it's not that, maybe it's where the blank plug things are in the front cover?!
2001 Range Rover P38 4.0 (with LPG)